Fluid actuated friction damper

Abstract

A fluid actuated friction damper having telescopically movable inner and outer bodies, the outer body having an elongated, continuous friction surface. The inner body includes a first set of friction shoes engageable with the continuous friction surface, a fluid pressure responsive device for exerting a normal force to urge the friction shoes against the continuous friction surface, and a shuttle device supporting the friction shoes for limited axial movement between end stops on the inner body. The inner body also provides fluid pressure communication between an external source of pressurized fluid and the fluid pressure responsive device when the shuttle is at one of the stops and for isolating the fluid pressure responsive device from the external source when the shuttle is moved from the one stop. A second set of friction shoes and a second fluid pressure responsive device for exerting a normal force to urge the second shoes against the continuous friction surface independently of the first set of friction shoes. The pressure responsive devices for both friction shoe sets are controlled by regulating the pressure of fluid supplied to the inner body from the external fluid pressure source but the first device is elastically biased to impose a friction drag on the shuttle. The normal force for both sets of friction shoes may be developed by a single externally controlled fluid pressure or, alternatively, by separate externally controlled fluid pressures. Also, the outer body is formed with an annular space between the friction surface and an outer wall to enable circulation of air for cooling.